Wolff Kishner Reaction – conversion of ketones/aldehydes to alkanes

by James

Description: The Wolff-Kishner is a reaction for converting carbonyls (such as ketones and aldehydes) into alkanes.
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Yes, but for a Wolff-Kishner reaction that does not imply the use of a strong base (i.e. hydroxide), would water be able to deprotonate that amine in step one to give the N-N double bond? I ask because in the synthesis of the drug Amiodarone, they do not specify basic conditions. Rather, they allude that they use hydrazine hydrate only.

Water isn’t basic enough to deprotonate. The pKa of the hydrazone hydrogens is about 22, whereas that of H3O(+) is -2. The equilibrium would be 24 orders of magnitude in opposition to the desired reaction.
I found a publicly available reference to the synthesis here: : http://bit.ly/J2TCRA
Although they don’t specifiy basic conditions in the reaction scheme, it’s not uncommon to leave out details such as base, solvent and heat. The Wolff Kishner is generally a very unfavorable reaction as it is – it requires heating at 180 degrees C or more – so I am nearly 100% certain that they merely omitted writing base in the scheme here.